4 
1 Battery won't charge.
So I just got my robot vacuum back after lending it to my brother.
Turned out it stopped working a while ago.
When I got it back I started to diagnose it.
The first thing I noticed was, when it's docked in the charginstation, it turns on and I can adopt it into the smart things app. The battery read 0% and no matter how long it charges it wouldn't go up.
So I started by disassembling the battery down to its individual cells. Turned out 5 out if 6 cells were completely dead (absolute 0 volts).
So I ordered some new cells and put the battery back together. The battery now shows 21,7 volts. But it still doesn't want to run outside the chargingstation.
When I use a multimeter on the battery, while it's connected to the chargingstation it shows about 25 volts on d+ to d- (the plugs from the vacuum to the PCB on the battery). And still 21,7 volts on b+ to b- (the spot welded tin to the battery). It has now charged for about 2 hours and it's still about 37% charged (so not getting charged).
I've tried to put the PCB under an thermal camera to see if anything gets hot, but it doesn't. Even with it plugged into the chargingstation, without the chargingstation or it disconnected from the robot. I've also tried to connect 21 volts 1 a with a powersupply connected both on d+ to d- and on b+ to b-, yet nothing gets hot.
Anyone have any idea on how I could fix this?
I'm pretty new to this stuff, but I do watch some youtubers like NorthridgeFix and TronicFix so I have some general idea.
Should I disconnect the cells again and maybe try injecting voltage over some of the chips on the PCB or check the resistance on some of the caps? If so i would love some guidence. I don't have a chip programmer yet, but I will order one sooner or later, if needed.
Image of the PCB here:
I'm also working on a guide on the disassembly of the batter here:
Disassembling Samsung Vacuum Battery VCA-RBT80 VR30T80313W/WA
crwdns2934109:0crwdne2934109:0
@cyrex86 since your guide is not yet made public, we can't preview unless you "allow" it. This does sound like a battery issue. Are you using all new cells? You have the same capacity cells as well as made sure they are fairly well balanced in regards to their charge? Not sure about this particular battery but it is possible that there are issues with the EEPROM on the battery that may have to be reset or reprogrammed. Nasty trick from the OEM's to make us have to buy their batteries vs. rebuilding. Let's see if we can find out more about that possibility. Looking forward to seeing your guide as well as your future repairs. It is appreciated.
Repair is War on Entropy!
crwdns2934271:0crwdnd2934271:0 oldturkey03 crwdne2934271:0
@oldturkey03 Ah darn I thought the link I made would make it accessible through the link. I'll make it public but just know it's not finished just yet. I was gonna take picture of the cutting tool I used etc to make it more filling.
crwdns2934271:0crwdnd2934271:0 CyReX crwdne2934271:0
@oldturkey03 The cells are all brand new (Atleast as much as we can thrust AliExpress), the exact same value and charged to their storage voltage when I got them (about 40 ish %). I put them into a charger (Liitokala, for about 10 minutes) that shows % and current voltage etc. The cells aren't perfectly balanced, but I would say they are within 5% of each other.
This is a link to the cells:
https://www.aliexpress.com/item/10050051...
And here are some pictures of the cells
https://imgur.com/a/OkaM7Mi
Old vs New cells:
https://imgur.com/a/Fg6yixH
crwdns2934271:0crwdnd2934271:0 CyReX crwdne2934271:0
Also, any reccomandations on an EEPROM? I was planning on getting this:
https://a.aliexpress.com/_EHHnFSY
Is this something I need, and is this even an EEPROM? 😋🙃
crwdns2934271:0crwdnd2934271:0 CyReX crwdne2934271:0
@cyrex86 I think you can actually add users to see your guide before making it public. Great job on pre-charging the cells, and that is the way I manage new cells as well. do my batteries. As for the programmer, it might help if you can identify the EEPROM on your board. There might just be a way to "reset" it and with some luck there might even be a datasheet that could help with that.
crwdns2934271:0crwdnd2934271:0 oldturkey03 crwdne2934271:0